Door operator

ABSTRACT

A door operator mounted upon an elongated rail and adapted to open and close an upwardly acting door having horizontally hinged sections supported on tracks. An elongated, helical spring extends lengthwise within the rail and is rotated by drive means mounted on the rail. A traveling nut is engaged with the helical spring and is connected to the door so that rotation of the helical spring causes the traveling nut to move lengthwise of the track to operate the door. Switch means are responsive to the compression and expansion of the spring to deenergize the drive means.

United States Patent Paul E. Pemberton Dallas;

Sheldon D. Loose, Carrollton, both of Text. [21] Appl. No. 856,555

[22] Filed Sept. 10, 1969 [45] Patented Sept. 28, 1971 [73] Assignee Overhead Door Corporation Dallas, Tex.

[72] Inventors [54] DOOR OPERATOR 10 Claims, 10 Drawing Figs.

[52] US. Cl 160/188,

160/189, 49/199, 49/360, 49/362 [51] Int. Cl E05f 15/16 [50] Field of Search 160/188,

2,530,629 11/1950 Pringle 49/199 X 2,550,721 5/1951 Ritter 160/188 X 2,637,550 5/1953 Ritter 160/188 2,883,182 4/1959 Bomemann 74/89.15 2,936,646 5/1960 Gould 49/360 X 3,220,718 11/1965 Wikkerink.. 160/188 X 3,383,577 5/1968 Ellmore 160/188 UX Primary ExaminerDennis L. Taylor Attorney-Woodhams, Blanchard & Flynn ABSTRACT: A door operator mounted upon an elongated rail and adapted to open and close an upwardly acting door having horizontally hinged sections supported on tracks. An elongated, helical spring extends lengthwise within the rail and is rotated by drive means mounted on the rail. A traveling nut is engaged with the helical spring and is connected to the door so that rotation of the helical spring causes the traveling nut to move lengthwise of the track to operate the door, Switch means are responsive to the compression and expansion of the spring to deenergize the drive means.

PATENIED SEF28 l97l 315085 1 2 vsum 1 or 3 DOOR OPERATOR FIELD OF THE INVENTION This invention relates to a door operator for an upwardly acting door and, more particularly, to a type thereof including an elongated helical spring drivingly engaged with a traveling nut mounted on a rail and connected to the door.

BACKGROUND OF THE INVENTION Door operators for moving a door between open and closed positions are old in the art, and many improvements have been made in such devices to increase the efficiency thereof. However, there has been an unfilled need for an operator, particularly for an upwardly acting door, having a better safety mechanism which would avoid injury to a person in the path of a moving door or damage to the door or the door operator mechanism when the movement of the door is obstructed during either opening or closing thereof. Many of the prior devices have been difficult to assemble due to the many parts, and they have been too bulky to ship in the assembled form. Thus, previously known door operators have been shipped in an unassembled form with an instruction booklet which could be followed only by a person experienced in installing door operators.

Further, during assembly of previously known door operators, the installer had to accurately set a complicated control mechanism for preventing the door from injuring persons or damaging objects in the path of the moving door or damaging the door operator mechanism. This adjustment involves a complicated procedure to assure proper operation and it is difficult to explain in instruction manuals. Therefore, this careful adjustment has been one of the major reasons why purchasers choose to have present door operator mechanisms installed by experienced personnel.

Most, if not all, door operators have some form of safety device which deenergizes the operator to stop the movement of the door if its movement is obstructed by an object or a person in the path of the door when it is being closed. In addition, limit switches are provided to deenergize the door operator when the door reaches the open or closed positions. However, most door operators have no provision for protecting the door operator or the door if the movement of the door is obstructed as it moves toward the open position. Also, existing devices for deenergizing the door operator, in case the door movement is obstructed, are often insufficiently sensitive to prevent at least some damage or injury if door movement is obstructed. This lack of sensitivity has become a particular problem where the doors are fabricated from lightweight and/or less durable materials such as aluminum, glass and/or fiberglass.

Existing door operators include at least some form of mechanical linkage between the door and the drive mechanism and, heretofore, this linkage has been substantially without resilience or cushioning means. Thus, stopping or starting of the door movement, particularly with medium or heavyweight doors, has imposed high initial loads on the drive mechanism and linkage, just to overcome inertia and initial friction. Obviously, as a result of this problem, it has been necessary to provide strength of materials and reinforced structure to meet these initial loads, even though the loads encountered between starting and stopping would require only a fraction of this strength.

Many existing door operators have noisy drive mechanism for moving the door-engaging linkage along a rail. Also, this drive mechanism creates a substantial amount of resistance to its own operation.

In the course of studying the foregoing problems, and others, it was found that, by using an elongated helical spring of suitable strength, all of these problems, and others, could be substantially reduced, if not eliminated. For example, the spring could be much lighter in weight than a conventional screw and still have adequate resistance to torsion. By this weight reduction, the strength, hence weight, of other associated parts could be reduced.

The spring could provide a natural cushion or resilience to initial starting and stopping loads while still retaining adequate resistance to excessive compression or extension. Moreover, the modest amount of permissible extension or compression could be advantageously used to trigger a highly sensitive safety shutoff switch for deenergizing the drive motor.

Furthermore, the spring could be coiled into a relatively small package also containing the guide rail which could be furnished in short sections. This would be impractical, if not impossible, with a conventional screw.

Accordingly, it is an object of this invention to provide a door operator which is relatively simple in construction, which comprises mostly factory assembled parts, which is furnished with a completely assembled drive mechanism, which can be compactly packaged at the factory, and which is ready and easy to install by the purchaser.

It is a further object of this invention to provide a door operator having a drive mechanism including a relatively lightweight, helical or spiral spring which signals an obstruction in the path of the door by an expansion or contraction of the spring, which cushions the initial shocks and loads created by the inertia of the moved parts and which operates quietly with a minimum of resistance due to friction and/or inertia, said operator having safety switch means which is responsive to, and includes mechanical amplification of, the compression or extension of said spring.

It is a further object of this invention to provide a door operator, as aforesaid, wherein the mechanism for adjusting the operator is uncomplicated and, therefore, simple to explain in an instruction manual.

Other objects and purposes of this invention will be apparent to persons acquainted with door operators of this general type upon reading the following specification and inspecting the accompanying drawings, in which:

FIG. 1 is a perspective view of a garage door assembly having an operator connected to the door and embodying the invention;

FIG. 2 is a broken, bottom view of the door operator;

FIG. 3 is a broken, side-elevational view of the door operator;

FIG. 4 is a sectional view taken along the line lV-IV in FIG. 3;

FIG. 5 is a top view of the helical spring and traveling nut, and a schematic illustration of the mechanism which is responsive to the compression and expansion of the spring to stop the movement of the door;

FIG. 6 is an electrical schematic of the circuitry for the door operator;

FIG. 7 is a sectional view taken along the line VllVllI IN FIG. 2;

FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 2;

FIG. 9 is an enlarged fragment of FIG. 2; and

FIG. 10 is a sectional view taken along the line X-X in FIG. 9.

Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words up," "down," right and left" will designate directions in the drawings to which reference is made. The words front" and rear" will designate the front and rear portions of the door operator, front being the left end of the mechanism illustrated in FIG. 3. The words in" and out" will refer to directions toward and away from, respectively, the geometric center of the device and designated parts thereof. Such terminology will include derivatives and words of similar import.

SUMMARY OF THE INVENTION The objects and purposes of the invention are met by providing a door operator having an elongated rail adapted to be supported from a mounting surface with means thereon for rotatably supporting an elongated drive member including rotatable drive means therefor. Traveling nut means is engaged by the drive member and the door so that rotation of the drive member by the drive means will cause the traveling nut and the door to move longitudinally of the rail. A portion of the drive member is axially flexible, and means responsive to axial movements thereof, caused by torsional stress thereon, stops the operation of the drive member.

DETAILED DESCRIPTION The door operator mechanism embodying the invention is connected in FIG. 1 to a garage door 11 having plural sections and adapted to be moved between a closed position across an opening 12 and a horizontal open position. For purposes of orientation, the garage 13 comprises a front wall 14, a sidewall 15, a ceiling l6 and a floor 17. In this particular embodiment, a pair of parallel, L-shaped tracks 18 and 19 are secured to the front wall 14 and the ceiling 16 in a conventional manner. The tracks 18 and 19 each have parallel vertical sections 21 and 22 extending parallel to the end wall 14 and horizontal sections 23 and 24 extending generally parallel with the ceiling 16. The rearward ends of the horizontal sections 23 and 24 are secured to the ceiling 16 by brackets 26 and 27, respectively, which brackets suspend the horizontal sections 23 and 24 below the ceiling 16 a predetermined distance.

In this particular embodiment, the door 11 comprises a plurality of horizontally hinged sections 28, each section having a plurality of wheel-holding brackets 29 thereon which rotatably support a wheel (not shown) engaged by one of the tracks 18 and 19 for guiding the door 11 between the closed position shown in FIG. 1 and an open position wherein the door is supported by the wheels on the horizontal sections 23 and 24 of the tracks 18 and 19.

The door operator mechanism 10 comprises an elongated rail 31 which, in this particular embodiment, is X-shaped as illustrated in FIG. 4 having four elongated, T-shaped and integral elements 32 through 35 projecting radially outwardly from a central hub portion 36. Each of the elements has a stem perpendicular to the next adjacent stem. The outer end flanges 37 through 40 of the elements 32 through 35 are arcuate and define portions of a cylindrical outer surface for the rail 31. In this particular embodiment, a gap is defined between each of the mutually adjacent edges of the arcuate flanges 37 through 40.

The elements 33 and 34 of the X-shaped rail 31 and the arcuate flanges 37 and 38 secured to the outer ends thereof respectively, define a channel 42 opening downwardly through the gap 41. The channel 42 extends the full length of the rail 31 and houses an elongated, channel-shaped and selflubricating plastic liner 43. The plastic liner 43 has an elongated and cylindrical opening 44 therethrough and a downwardly opening slot 46 that communicates with the gap 41 between the arcuate flanges 37 and 38.

The front end of the rail 31 may be mounted to the end wall 14 of the building 13 by a bracket 47 secured to the front end of the rail (FIGS. 2 and 3), by a plurality of screws 48. The bracket 47 comprises a nose 49 which projects forwardly of the bracket 47 and is looped to define an opening 51 therethrough. The rail 31 and liner 43 may be furnished in sections, preferably of dissimilar lengths.

A U-shaped bracket 52 (FIG. 2) is secured to the end wall 14 by a plurality of screws 53 and comprises a pair of parallel legs 54 and 56 located on opposite sides of the nose portion 49 of the bracket 47. A pin 57 is secured to the legs 54 and 56 and extends through the opening 51 and the nose portion 49 of the bracket 47 to support the front end of the rail 31. A mounting cushion 58 is provided in the opening 51 and has an opening 59 therethrough receiving the pin 57 to provide a resilient cushion for the rail 31.

A housing 61 is secured to the rail 31 and is suspended from the ceiling 16 by the brackets 62 and 63 illustrated in FIG. 1. The housing 61 comprises a horizontally disposed mounting plate 64 (FIGS. 2 and 8) and a cover 66 (FIG. 1) enclosing the bottom side of the mounting plate 64. A channel-shaped bracket 67 (FIG. 8) is secured to the mounting plate 64 by a plurality of screws 68 and projects downwardly therefrom as illustrated in FIG. 3. The lower flange 69 extends horizontally and frontwardly to support the rear end of the rail 31 and is secured thereto by a plurality of screws 71. Thus, the rail 31 and the housing 61 are supported above the horizontal sections 23 and 24 of the tracks 18 and 19.

A bearing housing 72 (FIGS. 3 and 8) is secured to the rear surface of the web of the bracket 67 by a plurality of screws 73 and houses a ball bearing 74. An opening 75 is provided in the web 70 of the bracket 67 in line with the bearing 74.

A torque transfer member 76 is rotatably supported by the bearing 74 in the bearing housing 72. The torque transfer member 76 comprises a coupling portion 77 and an elongated stub shaft 78 which extends rearwardly from the coupling portion through the bearing 74. A reversible electric motor 79, which is secured to the mounting plate 64 by any convenient means, has a shaft 81 operably coupled with the stub shaft 78 of the torque transfer member 76 by a coupling member 82. THus, energization of the electric motor 79 will effect a rotation of the torque transfer member 76.

An elongated drive member, here an axially compressible helical spring 83, is positioned within the cylindrical opening 44 (FIG. 4) in the plastic liner 43 in the rail 31 and extends the full length of the track. The rear end of the spring 83 is connected to the coupling portion 77 of the torque transfer member 76 so that rotation of the transfer member 76 also rotates the spring 83.

A traveling nut 86 is engaged with the spring 83 in the manner best illustrated in FIG. 5. The traveling nut 86 is preferably made of a flat piece of self-lubricating plastic material having a plurality of openings 87 which are aligned and longitudinally spaced a distance equal to the pitch of the helical spring 83. The traveling nut 86 projects through the slot 46 in the plastic liner 43 and the gap 41 between the arcuate flanges 37 and 38 of the X-shaped rail 31, as illustrated in FIG. 4, and is threaded into the openings 87 so that upon a rotation of the helical spring 83, the traveling nut 86 will move lengthwise of the rail 31. A pair of U-bolt clamps 84 and are adjustably positioned on the rail 31 and limit the travel of the nut 86.

A pair of plates 88 and 88 A (FIG. 3) are secured to the opposite sides of the lower end of the traveling nut 86 by a plurality of rivets or screws 89. A pin 91 is secured to and extends between the plates 88, and 88 A, and an elongated arm 92 is pivotally supported at one end on the pin 91. A right-angled extension member 93 is adjustably secured to the lower end of the arm 92 by a pair of fastening members 94. Openings 97 are provided in the arm 92 to permit attachment of the extension member 93 by the fastening member 94 at various locations on the arm 92.

A bracket 98 is mounted on the door 11 adjacent the upper end thereof by a plurality of screws 99. The extension member 93 is pivotally secured to the bracket by a pin 100. Thus, movement of the traveling nut 86. along the rail 31 will effect a movement of the upper end of the door 11 therewith. Since the door 11 is guided by the tracks 18 and 19 (FIG. 1), the door will be moved by the nut 86 between the opened and closed positions relative to the opening 12 in the building 13.

The control 101 (FIG. 2) functions not only as a safety device, but also as the limit switches to stop the motor when the door reaches the normal limits of its travel. The control 101 is mounted in the housing 61 and comprises a pair of horizontal arms 102 and 103 (FIG. 9) pivotally mounted on the mounting plate 64 by a bolt 104. The arm 102 has a limit switch 106 fastened thereto by bolts 107, and the arm 103 has a limit switch 108 fastened thereto by bolts 109. The arm 103 has a pair of integral, spaced flanges 111 and 112 (FIG. 7) at the outer end thereof which extend downwardly therefrom. The arm 102 has a pair of integral, spaced flanges 113 and 114 at the outer end thereof which extend downwardly therefrom.

A pair of spaced and parallel ears 116 and 117 (FIGS. 2 and 9) are fixedly connected to the mounting plate 64 and support a screw 118. A nut 119 is threadedly engaged with the screw 118 and is located between the flanges 111 and 112 (FIG. 7) so that rotation of the nut 119 relative to the screw 118 pivots the arm 103 about the axis of the bolt 104. One position of said arm appears in broken lines in FIG. 9. A pair of ears 121 and 122 (FIG. 9) is secured to the mounting plate 64 and they support a screw 123 thereon. A nut 124 is threadedly engaged with the screw 123 and is positioned between the flanges 113 and 114 on the arm 102. Thus, upon a rotation of the nut 124 relative to the screw 123, the arm 102 is pivoted about the axis of the bolt 104 to vary its position, one of which is shown in broken lines in FIG. 2.

A switch-actuating blade 126 (FIG. is pivotally mounted on the mounting plate 64 below the arms 102 and 103 by the same bolt 104 that pivotally supports the arms.102 and 103. The switch-actuating blade 126 has a pair of oppositely extending ends 127 and 128 which are engageable with the actuator elements on the limit switches 106 and 108, respectively. The end 127 of blade 126 (FIG. 8) has an opening 129 through which one end of an operator link rod 131 is received.

An actuator element 132 (FIG. 3) is sleeved around the spring 83 so that the spring 83 can rotate relative thereto. The actuator element 132 includes an arm 133 which projects downwardly through the gap 41 in the rail 31, as illustrated in FIGS. 2 and 3. An opening 134 is provided in the lower end of the arm 133 for reception of the other end of the link rod 131.

A pair of adjustment nuts 136 and 137 are secured to the spring 83 on opposite sides of the actuator element 132 to position the actuator element 132, hence the blade 126, properly relative to the limit switches 106 and 108. Thus, and as will be discussed hereinafter, movement of the actuator element 132 lengthwise of the rail 31, as the result of an extension or compression of the spring 83, will effect a pivotal movement of the switch-actuating blade 126 which operate one of the limit switches 106 or 108.

Referring now to the electrical schematic illustrated in FIG. 6, electrical power is supplied to the circuit 139 from a convenient source to lines L1 and L2. A pushbutton switch 141 (FIG. 1), which is mounted on the sidewall 15 of the building 13, is connected in series with a relay CR1 between the lines L1 and L2. The limit switches 106 and 108 are series connected in parallel with the pushbutton switch 141. A stepping relay CR2 is connected in parallel with the relay CR1. The nonnally open contact CR1-1 and a normally closed contact CR2-1 are series connected between the lower" winding of the reversible motor 79 and the line L1. The normally open contact CR1-1 and a normally open contact CR2-2 are series connected between the raise" winding of the reversible motor 79 and the line L2. The other side of the motor is connected to the line L2.

OPERATION The operation of the device embodying the invention will be readily apparent from the foregoing discussion. However, a summary of the operation will now be given for convenience.

The door 11 is illustrated as being in the closed position in FIG. 1, and it is assumed that the pushbutton switch 141 is the sole means of energizing the circuit 139, illustrated in FIG. 6. It is well known that radio-controlled units could be utilized to initiate energization of the circuit 139. Closing of the pushbutton switch 141 will simultaneously energize both of the relays CR1 and CR2 to close the normally open contact CR1-l, to open the normally closed contact CR2-l and to close the normally open contact CR2-2, whereby the raise" winding of the reversible electric motor 79 is energized. The motor 79 will rotate the shaft 81 whereby the helical spring 83 is rotated within the plastic liner 43. This will cause the traveling nut 86 to move from the front end of the rail 31, as illustrated in FIG. 3, toward the housing 61. A short time after the energization of the motor 79, the limit switch 106 will close (due to the stretching of the spring 83 as discussed later) so that the relays CR1 and CR2 will remain energized through the closed contacts of the limit switches 106and 108, when the pushbutton switch 141 is released. Upon the door reaching the raised position, the limit switch 108 will open (due to the compression of the spring 83, as discussed later) to deenergize the relays CR1 and CR2, whereby the contact CR1-l opens to deenergize the electric motor 79. The stepping relay CR2 will maintain the last condition of the contacts even though it is deenergized.

Referring to the schematic illustration of FIG. 5, clockwise rotation of the helical spring 83 (as seen from the right end thereof in FIG. 5) will urge movement of the traveling nut 86 in the direction of the arrow B. When the traveling nut 86 is stopped by the U-bolt clamp 85, the electric motor 79 will continue to rotate the helical spring 83 which will stretch the spring and thereby cause the nut 137 to effect a leftward movement of the link rod 131 in the direction of the arrow E to actuate, and thereby open, the limit switch 108. As stated above, opening of the limit switch 108 will deenergize the relays CR1 and CR2 to halt the movement of the traveling nut 86.

If the pushbutton switch 141 is operated again, the relays CR1 and CR2 will again be energized so that the normally open contact CR1-l will close. However, since the relay CR2 is a stepping relay, the now closed contact CR2-2 will open and the now open contact CR2-1 will close to energize the lower winding of the electric motor 79. Thus, the electric motor 79 will rotate the spring 83 in a counterclockwise direction to effect a movement of the traveling nut 86 leftwardly (FIG. 5) in the direction of the arrow D. When the traveling nut 86 is stopped by the U-bolt clamp 84, the electric motor 79 will continue to rotate so that the section of the spring 83 to the right of the traveling nut 86 will be compressed and the link rod 131 will be moved rightwardly in the direction of the arrow C (FIG. 5) to actuate the switch 106 to effect an opening thereof to deenergize the relays CR1 and CR2 to deenergize the motor 79.

To further understand the operation of the door operator mechanism, it will be assumed that prior to or during the aforedescribed lowering operation of the door 11, an object is placed in the path of the door 11. When the door 11 engages the object, movement of the traveling nut 86 in a leftward direction will be halted but the motor 79 will continue to rotate the spring 83 in a counterclockwise direction as illustrated in FIG. 5. Thus, the section of the spring 83 to the right of the traveling nut 86 will be compressed and thereby move the link rod 131 rightwardly in the direction of the arrow C to actuate the limit switch 106 to deenergize the relays CR1 and CR2, thereby deenergizing the motor 79. Upon an actuation of the pushbutton switch 141 again, the relays CR1 and CR2 will again be energized, as aforesaid, to raise the door 11 away from the object that it has engaged.

The same operational procedure, of stopping the door, will take place if an object is in the path of the door during an upward movement thereof and the control mechanism 101 will stop the movement of the door. Thus, if the door moves horizontally rather than vertically, as described above, the control device 101 will operate to stop the door 11 when moving in either horizontal direction.

The spring is selected so that it will cushion the shocks of starts and stops by compressing or extending slightly and thereby effectively slowing the rate of acceleration and deceleration during the intervals of time just prior to the start or or stop. This permits the use not only of a drive of less power than in conventional units, but also supporting structure of less strength, hence weight.

The spring distortions, which result in actuation of the switches 106 and 108, are mechanically amplified by the link rod 131 (FIG. 2) and its connections between the element 132 and blade 126. By appropriate positioning of the nuts 136 and 137 along the spring 83, the timing and balance of the switches 106 and 108 can be accurately and easily adjusted. By appropriate adjustment of the nuts 119 and 124, the sensitivity and response of the switches can be accurately and independently adjusted.

Although a particular preferred embodiment of the invention threadedly been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.

What is claimed is: l. A door operator, comprising: elongated rail means; elongated screw means rotatably supported by said rail means, said screw means being flexible throughout the full length thereof and capable of change in axial length;

drive means connected to said screw means for rotating same;

nut means mounted on said rail means and threadedly engaging said screw means, said nut means being urged lengthwise of said rail means in response to rotation of said screw means;

flange means on said nut means extending radially outwardly away from said screw means;

linkage means connected to said flange means on said nut means and adapted to engage a door; and

means responsive to a predetermined change in the axial length of said screw for stopping said drive means and the urging of said nut means.

2. A mechanism for moving an upwardly acting door between a substantially vertical closed position and a substantially horizontal open position, comprising:

an elongated rail means;

an elongated spiral member rotatably supported by said rail means, said spiral member being resiliently extensible and compressible lengthwise thereof throughout the full length thereof;

drive means connected to said spiral member for rotating same;

nut means mounted on said rail means and threadedly engaging said spiral member, said nut means being urged lengthwise of said spiral means in response to rotation of said spiral member;

flange means on said nut means extending radially outwardly away from said screw means;

linkage means connected to said flange means on said nut means and adapted for connection to said door; and

means responsive to a predetermined extension or compression of said spiral member due to an obstruction in the movement of said door for stopping rotation of said drive means.

3. A mechanism according to claim 2, wherein said rail means has an X-shaped cross section defining four lengthwise grooves, and said spiral member is disposed in the lowermost groove of said ecism means; and

wherein said nut means extends below said rail means for engagement with said linkage means.

4. A mechanism according to claim 2, wherein said drive means comprises a reversible electric motor having a shaft, and coupling means coaxially connecting said shaft to the end of said spiral member remote from the closed position of said door, said motor being connected to a source of electrical potential;

Wherein said responsive means includes switch means connected between said motor and said source, and switchactuating means responsive to said extension or said compression for operating said switch means, said switch means adapted to control said reversible electric motor to effect a subsequent rotation of said motor in one direction if the spiral member is extended and in the opposite direction if the spiral member is compressed.

5. In an operator for a door having linkage attached thereto, said operator having elongated rail means and rotary drive means, the combination comprising:

an elongated, helical and axially resilient spring extending lengthwise of and rotatably supported by said rail means,

said spring being adapted for connection to and rotation by said drive means; and

nut means mounted on said rail means and threadedly engaging said helicalspring, said nut means having flange means extending radially outwardly away from said spring,said nut means being yieldably urged lengthwise of said rail means in response to rotation of said helical spring, and said flange means on said nut means being adapted for connection to said linkage. 3

6. A device according to claim 5, wherein said rail means has wall means defining an elongated channel; and

including an elongated liner disposed within said channel and having an elongated slot opening through said channel, said liner being made of self-lubricating material and having an internal surface defining a cylinder, said helical spring being rotatably disposed within said liner said flange means in said nut means extending through said slot.

7. A mechanism according to claim 5, wherein said nut means includes a flat piece of self-lubricating plastic material and has a plurality of aligned and longitudinally spaced openings therethrough spaced a distance equal to the pitch of said spring, a number of convolutions of said spring corresponding to the number of said openings in said nut means extending through said openings whereby said nut means will move relative to said spring upon a rotation thereof with a minimum of friction.

8. A collapsible door operator assembly capable of being packaged compactly, comprising:

a plurality of separable track sections interconnected to define an elongated guide rail;

an elongated helical and axially resilient spring rotatably supported by said guide rail, said spring being capable of being coiled into a relatively small and compact arrangement;

drive means adapted to be connected to said screw means for rotating same;

nut means adapted to be mounted on said guide rail means and threadedly engaging said screw means, said nut means being urged lengthwise of said rail means in response to rotation of said screw means;

linkage means adapted to be connected to said nut means and further adapted to engage a door;

means responsive to a predetermined change in the axial length of said screw for stopping said drive means and the urging of said nut means; and

said plurality of separable track sections, said spring when in the coiled condition said drive means, said nut means, said linkage means and said responsive means all being adapted to be packaged in a small and compact arrangement for easy shipping purposes.

9. A mechanism for moving an upwardly acting door between a substantially vertical closed position and a substantially horizontal open position, comprising:

elongated rail means;

an elongated spiral member rotatably supported by said rail means, said spiral member being resiliently extensible and compressible lengthwise thereof;

drive means connected to said spiral member for rotating same, said drive means comprising a reversible electric motor having a shaft, and coupling means coaxially connecting said shaft to the end of said spiral member remote from the closed position of said door, said motor being connected to a source of electrical potential;

nut means mounted on said rail means and threadedly engaging said spiral member, said nut means being urged lengthwise of said rail means in response to rotation of said spiral member;

linkage means connected to said nut means and adapted for connection to said door;

means responsive to a predetermined extension or compression of said spiral member due to an obstruction in the movement of said door for stopping rotation in said drive means, said responsive means including switch means connected between said motor and said source, said switch means comprising arm means pivotally mounted adjacent said drive means, a pair of switches mounted upon said arm means and adjustment means for positioning said switches lengthwise of said rail, and switch actuating A mechanism responsive to said extension or said compression for operating said switch means, said actuating means comprising bar means pivotally mounted adjacent to and coaxially with said arm means, clamp means adjustably connected to said spiral member near said drive means, and linkage means connecting said bar means is adjustable lengthwise of said spiral member. 

1. A door operator, comprising: elongated rail means; elongated screw means rotatably supported by said rail means, said screw means being flexible throughout the full length thereof and capable of change in axial length; drive means connected to said screw means for rotating same; nut means mounted on said rail means and threadedly engaging said screw means, said nut means being urged lengthwise of said rail means in response to rotation of said screw means; flange means on said nut means extending radially outwardly away from said screw means; linkage means connected to said flange means on said nut means and adapted to engage a door; and means responsive to a predetermined change in the axial length of said screw for stopping said drive means and the urging of said nut means.
 2. A mechanism for moving an upwardly acting door between a substantially vertical closed position and a substantially horizontal open position, comprising: an elongated rail means; an elongated spiral member rotatably supported by said rail means, said spiral member being resiliently extensible and compressible lengthwise thereof throughout the full length thereof; drive means connected to said spiral member for rotating same; nut means mounted on said rail means and threadedly engaging said spiral member, said nut means being urged lengthwise of said spiral means in response to rotation of said spiral member; flange means on said nut means extending radially outwardly away from said screw means; linkage means connected to said flange means on said nut means and adapted for connection to said door; and means responsive to a predetermined extension or compression of said spiral member due to an obstruction in the movement of said door for stopping rotation of said drive means.
 3. A mechanism according to claim 2, wherein said rail means has an X-shaped cross section defining four lengthwise grooves, and said spiral member is disposed in the lowermost groove of said rail means; and wherein said nut means extends below said rail means for engagement with said linkage means.
 4. A mechanism according to claim 2, wherein said drive means comprises a reversible electric motor having a shaft, and coupling means coaxially connecting said shaft to the end of said spiral member remote from the closed position of said door, said motor being connected to a source of electrical potential; Wherein said responsive means includes switch means connected between said motor and said source, and switch-actuating means responsive to said extension or said compression for operating said switch means, said switch means adapted to control said reversible electric motor to effect a subsequent rotation of said motor in one direction if the spiral member is extended and in the opposite direction if the spiral member is compressed.
 5. In an operator for a door having linkage attached thereto, said operator having elongated rail means and rotary drive means, the combination comprising: an elongated, helical and axially resilient spring extending lengthwise of and rotatably supported by said rail means, said spring being adapted for connection to and rotation by said drive means; and nut means mounted on said rail means and threadedly engaging said helicalspring, said nut means having flange means extending radially outwardly away from said spring,said nut means being yieldably urged lengthwise of said rail means in response to rotation of said helical spring, and said flange means on said nut means being adapted for connection to said linkage. 3
 6. A device according to claim 5, wherein said rail means has wall means defining an elongated channel; and including an elongated liner disposed within said channel and having an elongated slot opening through said channel, said liner being made of self-lubricating material and having an internal surface defining a cylinder, said helical spring being rotatably disposed within said liner said flange means in said nut means extending through said slot.
 7. A mechanism according to claim 5, wherein said nut means includes a flat piece of self-lubricating plastic material and has a plurality of aligned and longitudinally spaced openings therethrough spaced a distance equal to the pitch of said spring, a number of convolutions of said spring corresponding to the number of said openings in said nut means extending through said openings whereby said nut means will move relative to said spring upon a rotation thereof with a minimum of friction.
 8. A collapsible door operator assembly capable of being packaged compactly, comprising: a plurality of separable track sections interconnected to define an elongated guide rail; an elongated helical and axially resilient spring rotatably supported by said guide rail, said spring being capable of being coiled into a relatively small and compact arrangement; drive means adapted to be connected to said screw means for rotating same; nut means adapted to be mounted on said guide rail means and threadedly engaging said screw means, said nut means being urged lengthwise of said rail means in response to rotation of said screw means; linkage means adapted to be connected to said nut means and further adapted to engage a door; means responsive to a predetermined change in the axial length of said screw for stopping said drive means and the urging of said nut means; and said plurality of separable tracK sections, said spring when in the coiled condition, said drive means, said nut means, said linkage means and said responsive means all being adapted to be packaged in a small and compact arrangement for easy shipping purposes.
 9. A mechanism for moving an upwardly acting door between a substantially vertical closed position and a substantially horizontal open position, comprising: elongated rail means; an elongated spiral member rotatably supported by said rail means, said spiral member being resiliently extensible and compressible lengthwise thereof; drive means connected to said spiral member for rotating same, said drive means comprising a reversible electric motor having a shaft, and coupling means coaxially connecting said shaft to the end of said spiral member remote from the closed position of said door, said motor being connected to a source of electrical potential; nut means mounted on said rail means and threadedly engaging said spiral member, said nut means being urged lengthwise of said rail means in response to rotation of said spiral member; linkage means connected to said nut means and adapted for connection to said door; means responsive to a predetermined extension or compression of said spiral member due to an obstruction in the movement of said door for stopping rotation in said drive means, said responsive means including switch means connected between said motor and said source, said switch means comprising arm means pivotally mounted adjacent said drive means, a pair of switches mounted upon said arm means and adjustment means for positioning said switches lengthwise of said rail, and switch actuating means responsive to said extension or said compression for operating said switch means, said actuating means comprising bar means pivotally mounted adjacent to and coaxially with said arm means, clamp means adjustably connected to said spiral member near said drive means, and linkage means connecting said bar means to said clamp means, one of said switches being operated when said clamp means is moved a predetermined distance lengthwise of said rail, said switch means controlling said reversible electric motor upon an appropriate actuation thereof to effect a subsequent rotation of said motor in one direction if the spiral member is extended and in the opposite direction if the spiral member is compressed.
 10. A mechanism according to claim 9, wherein said clamp means is adjustable lengthwise of said spiral member. 